403 Forbidden if the word "union" is found in url

Question

I noticed that if the word "union" is found/added on a url in my site, I'm getting a 403 forbidden error.

Here's a snapshot of an ajax (getjson) url with "union" added as GET variable: Now, if you alter the word "union" like "unsion" I'm getting a response but if the word "union" is in place and readable like "xxunionxx" the response is still forbidden.

My site runs on CI (CodeIgniter) Framework. I wonder if there's a filtering done over my server?

Thanks!

Answer 1

Thanks for the help! appreciate it. @MattGibson, right on ModSecurity! so support just disabled the mod_security rules and it's working fine now.